The aim of this research is to examine relationships between emotions, activities and reproductive hormone levels during the menstrual cycle in normal women. Women with regular menstrual cycles, between the ages of 21 and 40, not taking oral contraceptives, and involved in a steady heterosexual relationship are eligible to participate in the study. Subjects are interviewed (using the Psychiatric Status Schedule) to screen out women with psychopathology, severe marital/relationship difficulties, and drug or alcohol abuse. In a subsequent individual interview, each subject is questioned about her daily activities in order to collect information needed to develop data for the Social-Sexual Activities Log (SSAL). Then, for two and one half to three cycles, each subject fills out two questionnaires daily -- the Profile of Mood States (POMS) and the Social-Sexual Activities Log --and has blood samples drawn three or four times a week. In the SSAL, developed by us, the subject rates amount of time spent and degree of enjoyment associated with participation in daily activities in each of 8 categories: (1) work-related; (2) social activities at work; (3) housekeeping responsibilities; (4) heterosexual activities; (5) auto-erotic activities; (6) activities (non-sexual) with partner only; (7) social activities with others (or partner and others); (8) solitary activities.